package com.personal.common.filter;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

@SuppressWarnings({"rawtypes","unchecked"})
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper{

	HttpServletRequest orgRequest = null;

	public XssHttpServletRequestWrapper(HttpServletRequest request) {
		super(request);
		orgRequest = request;
	}

	/**
	 * 覆盖getParameter方法，将参数名和参数值都做xss过滤。<br/>
	 * 如果需要获得原始的值，则通过super.getParameterValues(name)来获取<br/>
	 * getParameterNames,getParameterValues和getParameterMap也可能需要覆盖
	 */

	public String getParameter(String name) {
		String value = super.getParameter(xssEncode(name));
		if (value != null) {
			value = xssEncode(value);
		}
		return value;
	}

	/**
	 * 
	 * @param name
	 * @return
	 */
	public String[] getParameterValues(String name) {
		String[] values = super.getParameterValues(name);
		if (values != null) {
			for (int i = 0; i < values.length; i++) {
				values[i] = xssEncode(values[i]);
			}
		}
		return values;
	}

	/**
	 * @return
	 */
	public Map<String, String[]> getParameterMap() {
		HashMap<String, String[]> paramMap = new HashMap(super.getParameterMap());
		paramMap = (HashMap<String, String[]>) paramMap.clone();
		for (Iterator iterator = paramMap.entrySet().iterator(); iterator.hasNext();) {
			Map.Entry<String, String[]> entry = (Map.Entry<String, String[]>) iterator.next();
			String[] values = entry.getValue();
			for (int i = 0; i < values.length; i++) {
				if (values[i] instanceof String) {
					values[i] = xssEncode(values[i]);
				}
			}
			entry.setValue(values);
		}
		return paramMap;
	}

	/**
	 * 覆盖getHeader方法，将参数名和参数值都做xss过滤。<br/>
	 * 如果需要获得原始的值，则通过super.getHeaders(name)来获取<br/>
	 * getHeaderNames 也可能需要覆盖
	 */

	public String getHeader(String name) {

		String value = super.getHeader(xssEncode(name));
		if (value != null) {
			value = xssEncode(value);
		}
		return value;
	}

	/**
	 * 将容易引起xss漏洞的半角字符直接替换成全角字符
	 * 
	 * @param s
	 * @return
	 */
	private static String xssEncode(String s) {
		if (s == null || "".equals(s)) {
			return s;
		}
		StringBuilder sb = new StringBuilder(s.length() + 16);
		for (int i = 0; i < s.length(); i++) {
			char c = s.charAt(i);
			switch (c) {
			case '>':
				sb.append('＞');// 全角大于号
				break;
			case '<':
				sb.append('＜');// 全角小于号
				break;
			case '\'':
				sb.append('‘');// 全角单引号
				break;
			case '\"':
				sb.append('“');// 全角双引号
				break;
			/*
			 * case '&': sb.append('＆');//全角 break;
			 */case '\\':
				sb.append('＼');// 全角斜线
				break;
			case '#':
				sb.append('＃');// 全角井号
				break;
			case '[':
				sb.append('【');// 全角斜线
				break;
			case ']':
				sb.append('】');// 全角斜线
				break;
			case '{':
				sb.append('｛');// 全角斜线
				break;
			case '}':
				sb.append('｝');// 全角斜线
				break;
			default:
				sb.append(c);
				break;
			}
		}
		return sb.toString().trim();
	}

	/**
	 * 获取最原始的request
	 * 
	 * @return
	 */
	public HttpServletRequest getOrgRequest() {
		return orgRequest;
	}

	/**
	 * 获取最原始的request的静态方法
	 * 
	 * @return
	 */
	public static HttpServletRequest getOrgRequest(HttpServletRequest req) {
		if (req instanceof XssHttpServletRequestWrapper) {
			return ((XssHttpServletRequestWrapper) req).getOrgRequest();
		}

		return req;
	}

}
